1. Field of the Invention
The apparatus of the present invention relates generally to the field of resistor manufacturing, and more particularly, but not by way of limitation, to an apparatus for producing a resistor having the heat-formed, substantially round heads on the ends of the leads thereof, molded, under a constant pressure, into electrical and mechanical contact with the resistive material to form an integral body.
2. Description of the Prior Art
In general, resistors are produced from a pair of leads having enlarged heads on the ends thereof, with the heads being embedded in some manner in a resistive material. Usually, the enlarged heads are either formed separately and attached to the lead in an appropriate manner, or are formed from the lead material itself by such means as swagging. Such methods, however, are often mechanically complicated and may incorporate mechanical weaknesses, such as along the attachment joint or the seams of the swagged head.
In the past, attempts have been made to produce resistors wherein the heads of the leads are molded, under a substantially predetermined pressure, into electrical and mechanical contact with the resistive material. The goal of such apparatus is to produce resistors having predictable resistance rather than a standard length. While generally acceptable, the mechanical pressure compensation means of the prior art apparatus, such as that disclosed in U.S. Pat. No. 2,261,916 issued to G. E. Megow et al on Nov. 4, 1941, are subject to substantial variations in performance.